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Optimization of protocols for DNA extraction from fecal samples

High-throughput sequencing offers new possibilities in molecular ecology and conservation studies. However, its potential has not yet become fully exploited for noninvasive studies of free–ranging animals, such as those based on feces. High–throughput sequencing allows sequencing of short DNA fragments and could allow simultaneous genotyping of a very large number of samples and markers at a low cost. The application of high throughput genotyping to fecal samples from wildlife has been hindered by several labor intensive steps. Alternative protocols which could allow higher throughput were evaluated for two of these steps: sample collection and DNA extraction. Two different field sampling and seven different DNA extraction methods were tested on grey wolf (Canis lupus) feces. There was high variation in genotyping success rates. The field sampling method based on surface swabbing performed much worse than the extraction from a fecal fragment. In addition, there is a lot of room for improvement in the DNA extraction step. Optimization of protocols can lead to very much more efficient, cheaper and higher throughput noninvasive monitoring. Selection of appropriate markers is still of paramount importance to increase genotyping success. informacion[at] Sarabia et al (2020) Towards high-throughput analyses of fecal samples from wildlife. Animal Biodiver Conserv 43.2: 271–283 Doi 10.32800/abc.2020.43.0271
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Avian eggshells coping with solar radiation

Avian eggshells coping with solar radiation

Solar radiation is an important driver of animal coloration, not only because of the effects of coloration on body temperature but also because coloration may protect from the deleterious effects of UV radiation. Indeed, dark coloration may protect from UV, but may increase the risk of overheating. In addition, the effect of coloration on thermoregulation should change with egg size, as smaller eggs have higher surface?volume ratios and greater convective coefficients than larger eggs, so that small eggs can dissipate heat quickly. To test whether the reflectance of eggshells, egg spottiness, and egg size of the ground?nesting Kentish plover Charadrius alexandrinus is affected by maximum ambient temperature and solar radiation at breeding sites, reflectance, both in the UV and human visible spectrum, spottiness, and egg size in photographs from a museum collection of plover eggshells were measured. Eggshells of lower reflectance (darker) were found at higher latitudes. However, in southern localities where solar radiation is very high, eggshells are also of dark coloration. Eggshell coloration had no significant relationship with ambient temperature. Spotiness was site?specific. Small eggs tended to be light?colored. Thermal constraints may drive the observed spatial variation in eggshell coloration, which may be lighter in lower latitudes to diminish the risk of overheating as a result of higher levels of solar radiation. However, in southern localities with very high levels of UV radiation, eggshells are of dark coloration likely to protect embryos from more intense UV radiation. Egg size exhibited variation in relation to coloration, likely through the effect of surface area?to?volume ratios on overheating and cooling rates of eggs. Therefore, differential effects of solar radiation on functions of coloration and size of eggshells may shape latitudinal variations in egg appearance in the Kentish plover. informacion[at] Gómez et al (2018) Latitudinal variation in biophysical characteristics of avian eggshells to cope with differential effects of solar radiation. Ecol Evol Doi 10.1002/ece3.4335